mips: allow the compiler to optimize memset, memcmp, memcpy for better performance and (in some instances) smaller code

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@20151 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 83 insertions, 0 deletions

diff --git a/target/linux/generic-2.6/patches-2.6.31/202-mips_mem_functions_performance.patch b/target/linux/generic-2.6/patches-2.6.31/202-mips_mem_functions_performance.patch
new file mode 100644
index 0000000000..6ea9ba51ee
--- /dev/null
+++ b/target/linux/generic-2.6/patches-2.6.31/202-mips_mem_functions_performance.patch
@@ -0,0 +1,83 @@
+--- a/arch/mips/include/asm/string.h
++++ b/arch/mips/include/asm/string.h
+@@ -133,11 +133,44 @@ strncmp(__const__ char *__cs, __const__ 
+ 
+ #define __HAVE_ARCH_MEMSET
+ extern void *memset(void *__s, int __c, size_t __count);
++#define memset(__s, __c, len)					\
++({								\
++	size_t __len = (len);					\
++	void *__ret;						\
++	if (__builtin_constant_p(len) && __len >= 64)		\
++		__ret = memset((__s), (__c), __len);		\
++	else							\
++		__ret = __builtin_memset((__s), (__c), __len);	\
++	__ret;							\
++})
+ 
+ #define __HAVE_ARCH_MEMCPY
+ extern void *memcpy(void *__to, __const__ void *__from, size_t __n);
++#define memcpy(dst, src, len)					\
++({								\
++	size_t __len = (len);					\
++	void *__ret;						\
++	if (__builtin_constant_p(len) && __len >= 64)		\
++		__ret = memcpy((dst), (src), __len);		\
++	else							\
++		__ret = __builtin_memcpy((dst), (src), __len);	\
++	__ret;							\
++})
+ 
+ #define __HAVE_ARCH_MEMMOVE
+ extern void *memmove(void *__dest, __const__ void *__src, size_t __n);
++#define memmove(dst, src, len)					\
++({								\
++	size_t __len = (len);					\
++	void *__ret;						\
++	if (__builtin_constant_p(len) && __len >= 64)		\
++		__ret = memmove((dst), (src), __len);		\
++	else							\
++		__ret = __builtin_memmove((dst), (src), __len);	\
++	__ret;							\
++})
++
++#define __HAVE_ARCH_MEMCMP
++#define memcmp(src1, src2, len) __builtin_memcmp((src1), (src2), (len))
+ 
+ #endif /* _ASM_STRING_H */
+--- a/arch/mips/lib/Makefile
++++ b/arch/mips/lib/Makefile
+@@ -3,7 +3,7 @@
+ #
+ 
+ lib-y	+= csum_partial.o delay.o memcpy.o memcpy-inatomic.o memset.o \
+-	   strlen_user.o strncpy_user.o strnlen_user.o uncached.o
++	   strlen_user.o strncpy_user.o strnlen_user.o uncached.o memcmp.o
+ 
+ obj-y			+= iomap.o
+ obj-$(CONFIG_PCI)	+= iomap-pci.o
+--- /dev/null
++++ b/arch/mips/lib/memcmp.c
+@@ -0,0 +1,22 @@
++/*
++ *  copied from linux/lib/string.c
++ *
++ *  Copyright (C) 1991, 1992  Linus Torvalds
++ */
++
++#include <linux/module.h>
++#include <linux/string.h>
++
++#undef memcmp
++int memcmp(const void *cs, const void *ct, size_t count)
++{
++	const unsigned char *su1, *su2;
++	int res = 0;
++
++	for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
++		if ((res = *su1 - *su2) != 0)
++			break;
++	return res;
++}
++EXPORT_SYMBOL(memcmp);
++